/**
* jQuery Lightbox
* Version 0.5 - 11/29/2007
* @author Warren Krewenki
*
* This package is distributed under the BSD license.
* For full license information, see LICENSE.TXT
*
* Based on Lightbox 2 by Lokesh Dhakar (http://www.huddletogether.com/projects/lightbox2/)
* Originally written to make use of the Prototype framework, and Script.acalo.us, now altered to use jQuery.
*
*
**/

(function($) {

    $.fn.lightbox = function(options) {
        // build main options
        var opts = $.extend({}, $.fn.lightbox.defaults, options);

        return this.each(function() {
            $(this).click(function() {
                // initalize the lightbox
                initialize();
                start(this);
                return false;
            });
        });

        /**
        * initalize()
        *
        * @return void
        * @author Warren Krewenki
        */

        function initialize() {
            $('#overlay').remove();
            $('#lightbox').remove();
            opts.inprogress = false;

            // if jsonData, build the imageArray from data provided in JSON format
            if (opts.jsonData && opts.jsonData.length > 0) {
                var parser = opts.jsonDataParser ? opts.jsonDataParser : $.fn.lightbox.parseJsonData;
                opts.imageArray = [];
                opts.imageArray = parser(opts.jsonData);
            }

            var outerImage = '<div id="outerImageContainer"><div id="imageContainer"><iframe id="lightboxIframe" /><img id="lightboxImage"><div id="hoverNav"><a href="javascript://" title="' + opts.strings.prevLinkTitle + '" id="prevLink"></a><a href="javascript://" id="nextLink" title="' + opts.strings.nextLinkTitle + '"></a></div><div id="loading"><a href="javascript://" id="loadingLink"><img src="' + opts.fileLoadingImage + '"></a></div></div></div>';
            var imageData = '<div id="imageDataContainer" class="clearfix"><div id="imageData"><div id="imageDetails"><span id="caption"></span><span id="numberDisplay"></span></div><div id="bottomNav">';

            if (opts.displayHelp)
                imageData += '<span id="helpDisplay">' + opts.strings.help + '</span>';

            imageData += '<a href="javascript://" id="bottomNavClose" title="' + opts.strings.closeTitle + '"><img src="' + opts.fileBottomNavCloseImage + '"></a></div></div></div>';

            var string;

            if (opts.navbarOnTop) {
                string = '<div id="overlay"></div><div id="lightbox">' + imageData + outerImage + '</div>';
                $("body").append(string);
                $("#imageDataContainer").addClass('ontop');
            } else {
                string = '<div id="overlay"></div><div id="lightbox">' + outerImage + imageData + '</div>';
                $("body").append(string);
            }

            $("#overlay").click(function() { end(); }).hide();
            $("#lightbox").click(function() { end(); }).hide();
            $("#loadingLink").click(function() { end(); return false; });
            $("#bottomNavClose").click(function() { end(); return false; });
            $('#outerImageContainer').width(opts.widthCurrent).height(opts.heightCurrent);
            $('#imageDataContainer').width(opts.widthCurrent);

            if (!opts.imageClickClose) {
                $("#lightboxImage").click(function() { return false; });
                $("#hoverNav").click(function() { return false; });
            }
        };

        function getPageSize() {
            var jqueryPageSize = new Array($(document).width(), $(document).height(), $(window).width(), $(window).height());
            return jqueryPageSize;
        };

        function getPageScroll() {
            var xScroll, yScroll;

            if (self.pageYOffset) {
                yScroll = self.pageYOffset;
                xScroll = self.pageXOffset;
            } else if (document.documentElement && document.documentElement.scrollTop) {  // Explorer 6 Strict
                yScroll = document.documentElement.scrollTop;
                xScroll = document.documentElement.scrollLeft;
            } else if (document.body) {// all other Explorers
                yScroll = document.body.scrollTop;
                xScroll = document.body.scrollLeft;
            }

            var arrayPageScroll = new Array(xScroll, yScroll);
            return arrayPageScroll;
        };

        function pause(ms) {
            var date = new Date();
            var curDate = null;
            do { curDate = new Date(); }
            while (curDate - date < ms);
        };

        function start(imageLink) {
            $("select, embed, object").hide();
            var arrayPageSize = getPageSize();
            $("#overlay").hide().css({ width: '100%', height: arrayPageSize[1] + 'px', opacity: opts.overlayOpacity }).fadeIn();
            imageNum = 0;

            // if data is not provided by jsonData parameter
            if (!opts.jsonData) {
                opts.imageArray = [];
                // if image is NOT part of a set..
                if (!imageLink.rel || (imageLink.rel == '')) {
                    // add single image to Lightbox.imageArray
                    opts.imageArray.push(new Array(imageLink.href, opts.displayTitle ? imageLink.title : ''));
                } else {
                    // if image is part of a set..
                    $("a").each(function() {
                        if (this.href && (this.rel == imageLink.rel)) {
                            opts.imageArray.push(new Array(this.href, opts.displayTitle ? this.title : ''));
                        }
                    });
                }
            }

            if (opts.imageArray.length > 1) {
                for (i = 0; i < opts.imageArray.length; i++) {
                    for (j = opts.imageArray.length - 1; j > i; j--) {
                        if (opts.imageArray[i][0] == opts.imageArray[j][0]) {
                            opts.imageArray.splice(j, 1);
                        }
                    }
                }
                while (opts.imageArray[imageNum][0] != imageLink.href) { imageNum++; }
            }

            // calculate top and left offset for the lightbox
            var arrayPageScroll = getPageScroll();
            var lightboxTop = arrayPageScroll[1] + (arrayPageSize[3] / 10);
            var lightboxLeft = arrayPageScroll[0];
            $('#lightbox').css({ top: lightboxTop + 'px', left: lightboxLeft + 'px' }).show();


            if (!opts.slideNavBar)
                $('#imageData').hide();

            changeImage(imageNum);
        };

        function changeImage(imageNum) {
            if (opts.inprogress == false) {
                opts.inprogress = true;
                opts.activeImage = imageNum; // update global var

                // hide elements during transition
                $('#loading').show();
                $('#lightboxImage').hide();

                if (!opts.ismati) {
                    $('#hoverNav').hide();
                    $('#prevLink').hide();
                    $('#nextLink').hide();
                }
                if (opts.slideNavBar) { // delay preloading image until navbar will slide up
                    // $('#imageDataContainer').slideUp(opts.navBarSlideSpeed, $.fn.doChangeImage);
                    $('#imageDataContainer').hide();
                    $('#imageData').hide();
                    doChangeImage();
                } else {
                    doChangeImage();
                }
            }
        };

        function doChangeImage() {

            imgPreloader = new Image();
            // once image is preloaded, resize image container
            imgPreloader.onload = function() {
                var newWidth = imgPreloader.width;
                var newHeight = imgPreloader.height;


                if (opts.fitToScreen) {
                    var arrayPageSize = getPageSize();
                    var ratio;
                    var initialPageWidth = arrayPageSize[2] - 2 * opts.borderSize;
                    var initialPageHeight = arrayPageSize[3] - 200;

                    if (imgPreloader.height > initialPageHeight) {
                        newWidth = parseInt((initialPageHeight / imgPreloader.height) * imgPreloader.width);
                        newHeight = initialPageHeight;
                    }
                    else if (imgPreloader.width > initialPageWidth) {
                        newHeight = parseInt((initialPageWidth / imgPreloader.width) * imgPreloader.height);
                        newWidth = initialPageWidth;
                    }
                }
                $('#lightboxImage').attr('src', opts.imageArray[opts.activeImage][0])
							       .width(newWidth).height(newHeight);
                resizeImageContainer(newWidth, newHeight);
            };
            if (opts.activeImage + 1 >= opts.imageArray.length) {
                imgPreloader.src = opts.imageArray[0][0];
                $("#nextLink").hide();
            }
            else {
                imgPreloader.src = opts.imageArray[opts.activeImage][0];
                $("#nextLink").show();
            }

            if (opts.activeImage <= 0) {
                $('#prevLink').hide();
            }
            else {
                $("#prevLink").show();
            }

        };

        function end() {
            disableKeyboardNav();
            $('#lightbox').hide();
            $('#overlay').fadeOut();
            $('select, object, embed').show();
        };

        function preloadNeighborImages() {
            if (opts.loopImages && opts.imageArray.length > 1) {
                preloadNextImage = new Image();
                preloadNextImage.src = opts.imageArray[(opts.activeImage == (opts.imageArray.length - 1)) ? 0 : opts.activeImage + 1][0]

                preloadPrevImage = new Image();
                preloadPrevImage.src = opts.imageArray[(opts.activeImage == 0) ? (opts.imageArray.length - 1) : opts.activeImage - 1][0]
            } else {
                if ((opts.imageArray.length - 1) > opts.activeImage) {
                    preloadNextImage = new Image();
                    preloadNextImage.src = opts.imageArray[opts.activeImage + 1][0];
                }
                if (opts.activeImage > 0) {
                    preloadPrevImage = new Image();
                    preloadPrevImage.src = opts.imageArray[opts.activeImage - 1][0];
                }
            }
        };

        function resizeImageContainer(imgWidth, imgHeight) {
            // get current width and height
            opts.widthCurrent = $("#outerImageContainer").outerWidth();
            opts.heightCurrent = $("#outerImageContainer").outerHeight();

            // get new width and height
            var widthNew = Math.max(350, imgWidth + (opts.borderSize * 2));
            var heightNew = (imgHeight + (opts.borderSize * 2));

            // scalars based on change from old to new
            opts.xScale = (widthNew / opts.widthCurrent) * 100;
            opts.yScale = (heightNew / opts.heightCurrent) * 100;

            // calculate size difference between new and old image, and resize if necessary
            wDiff = opts.widthCurrent - widthNew;
            hDiff = opts.heightCurrent - heightNew;

            $('#imageDataContainer').animate({ width: widthNew }, opts.resizeSpeed, 'linear');
            $('#outerImageContainer').animate({ width: widthNew }, opts.resizeSpeed, 'linear', function() {
                $('#outerImageContainer').animate({ height: heightNew }, opts.resizeSpeed, 'linear', function() {
                    showImage();
                });
            });

            // if new and old image are same size and no scaling transition is necessary,
            // do a quick pause to prevent image flicker.
            if ((hDiff == 0) && (wDiff == 0)) {
                if (jQuery.browser.msie) { pause(250); } else { pause(100); }
            }

            $('#prevLink').height(imgHeight);
            $('#nextLink').height(imgHeight);
        };

        function showImage() {
            $('#loading').hide();
            $('#lightboxImage').fadeIn("fast");
            updateDetails();
            preloadNeighborImages();

            opts.inprogress = false;
        };

        function updateDetails() {

            $('#numberDisplay').html('');

            if (opts.imageArray[opts.activeImage][1]) {
                $('#caption').html(opts.imageArray[opts.activeImage][1]).show();
            }

            // if image is part of set display 'Image x of x'
            if (opts.imageArray.length > 1) {
                var nav_html;

                nav_html = opts.strings.image + (opts.activeImage + 1) + opts.strings.of + opts.imageArray.length;

                if (!opts.disableNavbarLinks) {
                    // display previous / next text links
                    if ((opts.activeImage) > 0 || opts.loopImages) {
                        nav_html = '<a title="' + opts.strings.prevLinkTitle + '" href="#" id="prevLinkText">' + opts.strings.prevLinkText + "</a>" + nav_html;
                    }

                    if (((opts.activeImage + 1) < opts.imageArray.length) || opts.loopImages) {
                        nav_html += '<a title="' + opts.strings.nextLinkTitle + '" href="#" id="nextLinkText">' + opts.strings.nextLinkText + "</a>";
                    }
                }

                $('#numberDisplay').html(nav_html).show();
            }

            if (opts.slideNavBar) {
                $("#imageData").slideDown(opts.navBarSlideSpeed);
            } else {
                $("#imageData").show();
            }

            var arrayPageSize = getPageSize();
            $('#overlay').height(arrayPageSize[1]);
            updateNav();
        };

        function updateNav() {
            if (opts.imageArray.length > 1) {
                $('#hoverNav').show();

                // if loopImages is true, always show next and prev image buttons 
                if (opts.loopImages) {
                    $('#prevLink,#prevLinkText').show().click(function() {
                        changeImage((opts.activeImage == 0) ? (opts.imageArray.length - 1) : opts.activeImage - 1); return false;
                    });

                    $('#nextLink,#nextLinkText').show().click(function() {
                        changeImage((opts.activeImage == (opts.imageArray.length - 1)) ? 0 : opts.activeImage + 1); return false;
                    });

                } else {
                    // if not first image in set, display prev image button
                    if (opts.activeImage != 0) {
                        $('#prevLink,#prevLinkText').show().click(function() {
                            changeImage(opts.activeImage - 1); return false;
                        });
                    }

                    // if not last image in set, display next image button
                    if (opts.activeImage != (opts.imageArray.length - 1)) {
                        $('#nextLink,#nextLinkText').show().click(function() {

                            changeImage(opts.activeImage + 1); return false;
                        });
                    }
                }

                enableKeyboardNav();
            }
        };

        function keyboardAction(e) {
            var o = e.data.opts
            var keycode = e.keyCode;
            var escapeKey = 27;

            var key = String.fromCharCode(keycode).toLowerCase();

            if ((key == 'x') || (key == 'o') || (key == 'c') || (keycode == escapeKey)) { // close lightbox
                end();
            } else if ((key == 'p') || (keycode == 37)) { // display previous image
                if (o.loopImages) {
                    disableKeyboardNav();
                    changeImage((o.activeImage == 0) ? (o.imageArray.length - 1) : o.activeImage - 1);
                }
                else if (o.activeImage != 0) {
                    disableKeyboardNav();
                    changeImage(o.activeImage - 1);
                }
            } else if ((key == 'n') || (keycode == 39)) { // display next image
                if (opts.loopImages) {
                    disableKeyboardNav();
                    changeImage((o.activeImage == (o.imageArray.length - 1)) ? 0 : o.activeImage + 1);
                }
                else if (o.activeImage != (o.imageArray.length - 1)) {
                    disableKeyboardNav();
                    changeImage(o.activeImage + 1);
                }
            }
        };

        function enableKeyboardNav() {
            $(document).bind('keydown', { opts: opts }, keyboardAction);
        };

        function disableKeyboardNav() {
            $(document).unbind('keydown');
        };

    };

    $.fn.lightbox.parseJsonData = function(data) {
        var imageArray = [];

        $.each(data, function() {
            imageArray.push(new Array(this.url, this.title));
        });

        return imageArray;
    };

    $.fn.lightbox.defaults = {
        fileLoadingImage: 'images/loading.gif',
        fileBottomNavCloseImage: 'images/closelabel.gif',
        overlayOpacity: 0.8,
        borderSize: 10,
        imageArray: new Array,
        activeImage: null,
        inprogress: false,
        resizeSpeed: 350,
        widthCurrent: 250,
        heightCurrent: 250,
        ismati: false,
        xScale: 1,
        yScale: 1,
        displayTitle: true,
        navbarOnTop: false,
        slideNavBar: false, // slide nav bar up/down between image resizing transitions
        navBarSlideSpeed: 350,
        displayHelp: false,
        strings: {
            help: '',
            prevLinkTitle: '上一张图片',
            nextLinkTitle: '下一张图片',
            prevLinkText: '&laquo; 上一张',
            nextLinkText: '下一张 &raquo;',
            closeTitle: '关闭',
            image: '图片 ',
            of: ' / '
        },
        fitToScreen: false, 	// resize images if they are bigger than window
        disableNavbarLinks: false,
        loopImages: false,
        imageClickClose: true,
        jsonData: null,
        jsonDataParser: null
    };

})(jQuery);
